Combustor basket structure



Jan. 22, 1957 KROQN 2,778,192

COMBUSTOR BASKET STRUCTURE Filed Oct. 22, 1953 2 Sheets-Sheet l EXHAUST EXHAUST REGENERATOR INVENTOR PIETER J. KROON ATTQRNEY Jan. 22, 1957 P. J. KROON 2,778,1Q2

COMBUSTOR BASKET STRUCTURE Filed Oct. 22, 1953 2 Sheets-Sheet 2 INVENTOR PIETER J. KROON MSXIY-YI ATTORNEY COMBUSTOR BASKET STRUCTURE Pieter J. Kroon, Swarihmore,

house Electric Corporation, poration of Pennsylvania Pa., assignor to Westing- East Pittsburgh, Pa., a cor- This invention relates to a combustor basket structure, more particularly to a combustor basket structure for a gas turbine or the like, and has for an object to provide an improved combustor basket structure.

Another object is to provide a combustor basket structure in which the elements forming the combustion chamber may be easily and expeditiously removed for servicing.

A more specific object is to provide a combustor basket structure in which the elements forming the combustion chamber are arranged in a manner, to permit free radial and longitudinal expansion, thereby minimizing warping and distortion and damage incident thereto.

Yet another object is to provide a combustor basket apparatus for a gas turbine in which a plurality of tubular elements forming the combustion chamber are detachably supported in a supporting structure, which structure may be easily removed from the turbine for individual servicing of the elements.

These and other objects are effected by the invention as will be apparent from the following description taken in connection with the accompanying drawings, forming a part of this application, in which:

Fig. l is a diagrammatic longitudinal sectional view of a gas turbine having the improved combustor basket structure incorporated therein;

Fig. 2 is a perspective view, on a larger scale, showing the combustor basket structure removed from the turbine;

Fig. 3 is a cross-sectional view taken on line III-III of Fig. 2;

Fig. 4 is a longitudinal sectional view of the combustor basket structure, on a still larger scale, in assembled relation with the combustor shell shown in Fig. 1, only the adjacent shell structure being shown; and

Fig. 5 is an exploded perspective view of the combustor basket structure.

Referring to Fig. 1, the invention has been incorporated for illustration purposes in a gas turbine power plant of recently proposed design comprising a horizontally disposed inner casing structure, generally indicated at 10, having a compressor casing portion 11 with an inlet 12 and an annular compressor discharge outlet 13, an intermediate casing portion 15 forming an annular transition chamber 16 which communicates with the compressor discharge outlet 13 and with diametrically opposite branch portions of an outlet conduit 17, and a turbine portion 18. Formed in the forward or left-hand end of the intermediate casing portion 15 and in encompassing relation with respect to adjacent areas of the compressor portion thereof, is an outer substantially annular hot air manifold 20 having diametrically opposed inlet passages formed in a branched conduit 21. The casing structure includes an annular interior wall 22 for preventing communication between the hot air manifold 20 and the transition chamber 16.

A plurality of circumferentially spaced combustor atent' 2,778,192 Patented Jan. 22, 1957 basket structures, generally indicated 25 and representing the subject matter of the invention, are mounted in the casing structure 10 with their axes inclined relative to the horizontal axis of the casing structure. Each of the combustor basket structures 25 is provided with a plurality of perforated or foraminous tubular members 25a, 25b, 25c and 25d arranged in end-to-end relation to each other and forming a fuel combustion chamber. The improved combustor basket structure will be subsequently fully described.

The combustor basket structures 25 are disposed in the hot air manifold 20 and extend in radially outward overhanging relation with a substantial length of the com pressor portion 11 of the casing structure. The tubular member 25d of each combustor basket structure is in registry with a tubular portion 27 of an associated transition member 28. The transition members 28 have their downstream ends reduced in. radial direction and broadened in circumferential direction to provide a plurality of arcuate nozzle portions 280 adjacent the turbine casing portion 18, which in turn contains an annular turbine nozzle vane assembly 29.

The compressor portion 11' of the casing structure houses an axial-flow compressor 32, including a bladed rotor 33, to which is suitably bolted a tubular shaft 34 and a turbine rotor 36. The latter is adapted to be operated in the usual manner by gases supplied from the combustor basket structures through the nozzle assembly 29, for driving the compressor rotor 33. In the power plant illustrated, a second turbine 38, adapted to deliver shaft power for any desired use, is mounted coaxially of the turbine rotor 36 for independent operation by the exhaust gases which are then discharged to a conduit 40.

A heat exchanger or regenerator 42 may, if desired, be associated with the gas turbine power plant just described, for utilizing the exhaust gases to heat air delivered by the compressor prior to its introduction into the combustion apparatus. The regenerator 42 may be of any desired type and is arranged to receive the exhaust gases from the conduit 40 and to discharge them to atmosphere after the major part of the heat contained therein is expended in heating the compressor air fed through the regenerator. The compressed air conduits 17 and 21 are connected to the regenerator 42, whereby the air flowing therethrough is heated by the exhaust gases in a manner well known in the art.

The operation of the power plant described above, briefly is as follows: Air entering the inlet 12 is compressed by the compressor 32 and delivered through the compressor discharge passage 13 to the transition chamber 16 where it flows around the spaced tubular transition portions 27 of the transition members 28. From the transition chamber 16 the air under pressure flows through the branched conduits 17 to the regenerator 42 where it is heated by the exhaust gases and thence flows through the conduits 21 to the hot air manifold 20. The preheated air is admitted through the apertures 26 into the tubular members 25a, 25b, 25c and 25d of the combustor basket structures, for supporting combustion of fuel which is supplied thereto by way of fuel conduits 43. The resultant hot combustion products and gases under pressure are somewhat cooled during flow through the tubular portions 27 of the transition members 28, owing to constant circulation thereabout of compressed air flowing through the transition chamber 16 as previously explained.

Upon expansion of the hot motive gases through the communications associated with the turbine rotor 36 and through those of the turbine 38, the exhaust gases are conducted by way of the conduit 40 through the regenerator 42.

Referring to Figs. 2, 3, 4 and 5, the combustor basket structure 25 comprises a unitary open framework 44 for detachably supporting the tubular members 25a, 25b, 25c and 25d.

.- The framework 4-4 has a plurality of, in this instance three, longitudinal channel members 45 disposed parallel to each other and angularly spaced about a common axis with their channels 46 facing radially inwardly towards the longitudinal axis of the framework. The channel members 45 are integrated by a plurality of annular bands 47 which encircle the channel members 45 and are attached thereto, for example, by welding at each point of contact. A closure plate 48 disposed transversely of the longitudinal axis of the framework 44 is attached to the adjacent ends of the channel members 45 by means of an annular member 49 of angular cross section, the member 49 being welded or otherwise attached to the channel members 45 and the closure plate 48 being attached to the annular member 49 by means of bolts 50 or the like.

The tubular members 25a, 25b, 25c and 25d are of difierent diameters and are graduated in ascending order from left to right, as viewed in the figures. They are provided with sets of arms 51a, 51b, 51c and 51d, respectively, which extend radially outwardly therefrom and are provided with axially extending terminal portions 52a, 52b, 52c and 52d disposed on common lines parallel to the axes of the tubular members and arranged for slidable engagement with the respective channels 46 of the channel members 45. If desired, some of the tubular members may be formed with a longer axial length than others. In such cases it may be desirable to add further radially outwardly extending arms such as, for example, radial arms 53b, 53c and 53d disposed in axial alignment with the first-mentioned radial arms and adapted to engage the respective channels 46 to more rigidly secure the longer tubular members in the unitary framework 44. Also, an end member 55 of hemi-spherical shape may be desirably provided to serve as a partial closure for the combustion chamber formed by the tubular members 25a, 25b, 25c and 25d. The hemi-spherical member 55 is also provided with a set of radial arms 55a arranged to slidably engage the channels 46 and. to centrally position the member 55 in the framework. The member 55 is preferably of smaller diameter than its adjacent tubular member 25:: and is provided with a central opening 55b through which the fuel conduit 43 extends.

The closure plate 48 is further provided with a centrally mounted plate member 56 having a central opening therethrough for reception of the fuel conduit 43. The closure plate may also be provided with another opening for supporting an ignitor '(not shown). The plate 56 may be detachably mounted to the closure plate 48 by means of screws 57 or the like. a

The tubular portion 27 of the associated transition member 23 is also provided with a set of radial arms 27a having axially extending terminal portions 27b arranged to slidably engage the channels 46 of the channel members 45.

As best shown in Figs. 2 and 4, the spherical memthe framework 44 when the combustor basket structure is mounted in the turbine. As shown in Figs. 1 and 4, the combustor basket structure is inserted through an opening in the casing 15 and is positioned in the hot air manifold by means of a series of bolts 59 received in the casing 10 and clamping the closure plate 43 thereto.

As best shown in Fig. 4, the diameters of the tubular members a, 25b, 25c and 25d and of the member 55 are such that annular air passages are formed between adjacent members permitting the entry of air into the combustion chamber formed thereby and further permitting radial and axial expansion of the tubular members and the end member incurred during operation of the turbine. Such radial expansion merely serves to reduce the radial width of the annular air passages between the tubular members and the axial elongation causes a larger degree of overlapping between the tubular members. Metal-to-metal contact between the adjacent tubular members and stresses incident thereto is thus obviated.

Also, the radial arms of the member 55 and the tubular members extend radially outwardly to a slightly less degree than essential for full engagement with the channels 46, thereby providing a clearance space 60b between the radial arms and the bottoms of the channels 46. During operation and heating incident thereto, the space 60b is taken up somewhat by the radial expansion of the radial arms. However, the space 60b may be made sufficiently large to obviate any stresses upon the channel members by radial expansion of the radial arms.

Should a tubular member be burnt or otherwise damaged in service, the entire combustor basket structure 25 may be removed through the opening in the casing 10 after the bolts 59 are removed. The combustor basket structure 25 may be removed from the turbine in its entirety and since the framework 44 is entirely open, the damaged member may be readily perceived. The tubular members 25d, 25c, 25b and 25a, and the end member 55 may be removed from the framework 44, in the above order, merely by grasping them individually and sliding them axially outwardly to the right, as viewed in Fig. 5. it is then an easy matter to provide a replacement for the damaged member in its proper position in the framework 44 by inserting it therein in its proper sequence.

It will be noted that, although the transition members 28 serve to retain the tubular members in the associated framework 44 while the combustor basket structures are 7 mounted in the turbine, the tubular elements are comher 55 and the tubular members 25a, 25b, 25c and 2511 are slidably received in the framework 44 and are positioned therein in proper end-to-end overlapping relation by abutment of the terminal portions 55a, 52a, 52b, 52c and 52d with each other. The terminal portions 52a52d may be made slightly shorter in axial length than required, so that when the combustor basket structure 25 is cool a small end clearance a is provided. As the structure becomes heated to operating temperature, axial expansion of the portions 52a52d will reduce the clearance 60a without stressing the structure. It will be noted that the terminal portions 27b of the transition members 28 are partially received in the framework 44 and abut the arms 53d of the tubular member 25d, while the annular angle member 49 abuts the terminal portions 55a of the spherical member. The transition member 28 is fixed to the turbine casing 15 and serves as a positive abutment retaining the tubular members within pletely accessible for removal from the framework 44 and may be removed therefrom without tools of any sort, once the combustor basket structures are removed from the turbine casing 10.

It will now be seen that the invention provides a combustor basket structure which is comparatively simple to manufacture and devoid of stresses and warpage of its components when in use. Although the components thereof are subjected to high temperatures, they are free to expand in radial directions as well as axial directions without imposing stresses on associated components. With such an arrangement, the tubular members forming the combustion chamber may be made of relatively light gauge sheet metal, or, if desired, some of the members may be made of more durable material than others when indicated by high temperature conditions.

It will also be seen that, although the invention provides a combustor basket structure which is highly durable and has a long trouble-free life, it is peculiarly adapted to facilitate servicing and replacement of the tubular members in the event that damage is incurred therein.

While the invention has been shown in but one form, it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various changes and modifications without departing from the spirit thereof.

What is claimed is:

l. A combustor basket structure for a gas turbine or the like comprising an open framework including a plurality of elongated members disposed substantially parallel to each other in angularly spaced relation about a common axis, means connecting said elongated members to each other, a plurality of tubular members supported in said framework in overlapping end-to-end relation with each other and providing a combustion chamber wall, and mutually cooperating keying means provided on said elongated members and each of said tubular members for centrally positioning said tubular members in said framework, said tubular members being removable from said framework by movement in axial direction.

2. A combustor basket structure for a gas turbine or the like comprising an open framework including a plurality of channel members disposed substantially parallel to each other in angularly spaced relation about a common axis, a plurality of annular members disposed substantially normal to said common axis and connected to said channel members, said channel members being disposed with the channels facing radially inwardly, and said framework having a central opening at one end, a plurality of tubular members detachably supported in said framework in axial alignment with each other and pro viding a combustion chamber wall, each of said tubular members having a plurality of radially extending support arms, each of said arms having a terminal portion, said terminal portions being in keying engagement with the channels of said channel members, said tubular members being removable from said framework through said central opening by sliding movement in axial direction but being restrained against rotational movement by the keying engagement between said channel members and said terminal arm portions.

3. A gas turbine having a casing defining an air chamber, said casing having an opening, a combustor basket structure extending through said opening into said air chamber and including a closure member closing said opening, said combustor basket structure comprising an open unitary framework including a plurality of elongated members disposed in angularly spaced relation to each other about a common longitudinal axis, a plurality of annular members encircling said longitudinal mem bers and attached thereto, said closure member being attached to one end of said framework, a plurality of tubular members supported in said framework in overlapping end-to-end relation to each other and forming a combustion chamber, and mutually cooperating keying means provided on said elongated members and said tubular members, said keying means maintaining said tubular members in a central position in said framework, said casing having a fixed transition member provided with a tubular portion disposed in axial alignment with said combustor basket structure and in engagement with the other end of the same, said transition member retaining said tubular members in said framework but permitting limited axial movement therebetween, said combustor basket structure being removable from said casing through said opening, whereupon said tubular members are axially removable from said framework through said other end of the framework.

4. The structure recited in claim 3 in which said tubular members comprise a plurality of radially extending arms, and said keying means comprises the terminal portions of said arms and longitudinal channels formed in said elongated members, said terminal portions being slidably received in said channels.

5. The structure recited in claim 4 in which said transition member comprises a plurality of radially extending arms having their terminal portions slidably received in said channels, said tubular members being of graduated cross-sectional area in ascending order in the direction toward said transition member, and the terminal portions of a plurality of said arms extending axially and positioning said tubular members axially in said framework.

6. A combustor basket structure for a gas turbine or the like comprising a framework having a plurality of elongated keying members disposed substantially parallel to each other in angularly spaced relation about the longitudinal axis of said framework, said keying members extending substantially the entire length of said framework, a plurality of tubular members supported in said framework in end-to-end relation with each other and providing a combustion chamber wall, and means provided on each of said tubular members and cooperating with said keying members for centrally positioning said tubular members in said framework, said framework having an opening at one end and said tubular members being disengageable from said keying members and removable from said framework by movement in an axial direction toward said opening.

References Cited in the file of this patent UNITED STATES PATENTS 

